Research Paper

Authors: Arantxa Daza Perea

Abstract

This paper aims to highlight developments in archaeological knowledge relating to dog remains found in deposits from Late Prehistoric contexts at sites along the Iberian Peninsula. Preliminary results from ongoing osteometric and 2D Geometric Morphometric studies applied to these remains are here presented and discussed to contextualize future studies by the author.

Introduction

Social inequality emerged during the Iberian Chalcolithic in the 3rd millennium BCE, and further widened during the Bell-Beaker horizon when preferential treatment of a select few of the human population took place. This inequality, however, is only observed in the funerary record, where differences in tomb types and grave goods are noted (Harrison 1977, Delibes 1977, Díaz-del-Río & García Sanjuán 2006). During this period, settlements comprise of features such as pits, hut structures and ditched or walled enclosures; the defensive character of the latter has been widely discussed in recent years (Díaz del Río 2003, Molina et al. 2004, Kunst 2010, Márquez & Jiménez 2010). Settlement patterns and inhumations changed slightly during the Bronze Age: new spaces were occupied and funerary rituals also changed (Bellido 1995, Benítez de Lugo 2011, Serrano 2012). Faunal studies have shown that domestic species were consumed regularly (Morales & Liesau 1994, Rodríguez & García 2011, Liesau 2011). However, dog remains are often retrieved from different conditions and contexts, suggesting that they were subject to different treatment compared to other species.

Earlier studies have documented the presence of dog remains placed in late prehistoric deposits at settlements along the Iberian Peninsula (Daza 2015: 14–20). The findings from the Polideportivo de Martos suggest that a dog phenomenon emerged during the Late Neolithic, given the proliferation of the practice of depositing the remains of complete dogs, or parts of them, inside structures (Lizcano et al. 1991, Lizcano & Cámara 2003) (Figure 1). This article outlines Late Prehistoric sites across the Iberian Peninsula from which deposits of dog remains have been documented. Secondly, it presents preliminary results from traditional osteometry and two-dimensional (2D) landmark-based geometric morphometric studies, which form part of the author’s doctoral research. In order to better understand this dog phenomenon, dog remains (mostly from Camino de las Yeseras) were analysed using morphological criteria to categorise the specimens.

Dog remains found in Iberian settlements and their types of deposits (dogs in funerary contexts, dogs in outstanding locations, dogs in pits) The numbers in the left column correspond to those in Figure 1.

Our study centres on the settlement of Camino de las Yeseras, a Chalcolithic ditched enclosure located in the region of Madrid (Figure 1: 5), at the centre of the Iberian Peninsula (Liesau et al. 2008, Blasco et al. 2011). Several dog remains were documented during the site’s excavation, and from these, we were able to infer the presence of three types of contexts in which dog remains were deposited: funerary contexts, outstanding locations and pits.

Based on this study of Camino de las Yeseras’ deposit types, we were able to identify these three same categories at other important sites in the Iberian Peninsula (Table 1).

During the Chalcolithic the presence of dog remains in funerary contexts, observed through the recovery of dog skeletons associated with tombs, is relatively frequent in the Iberian archaeological record. Complete articulated dog skeletons have been found in burials at sites such as El Cerro de la Cabeza in Ávila (Figure 1: 12, Table 1: 12), (Fabián & Blanco 2012: 110) and Casa Noguera in Murcia (Figure 1: 17, Table 1: 19), (García & Martínez, 2004). Similar practices have also been documented in collective burials such as those of Camino del Molino in Murcia (Figure 1: 16, Table 1: 18), (Lomba et al. 2009: 153), El Perdido (Figure 1: 6, Table 1: 4), (Daza 2005) and Camino de las Yeseras in Madrid (Figure 1: 5, Table 1: 5), (Daza 2011). The latter contains the remains of two dogs with evidence of perimortem violence, and had been deposited at the intersection of two pits within a Bell-Beaker burial (Figure 2) (Daza 2011: 215, Liesau et al. 2013: 283).

Other examples falling under the category of dogs in funerary contexts include Bronze Age tombs, especially child burials, such as at Caserío de Perales del Río (Figure 1: 10, Table 1: 6) (Blasco et al. 1991: 56) and Camino de las Yeseras (Figure 1: 5, Table 1: 5), (Daza 2011: 215). This latter site includes a complete dog skeleton, together with other faunal remains, accompanying a child burial.

The presence of dogs in outstanding locations is a noteworthy occurrence (Liesau et al. 2013–2014: 53–54, 66). Dog remains have been linked to areas whose location or arrangement characteristics are extraordinary within the settlement. These relate to distinctive ideology, ritual purposes or the management of the space by human populations (i.e. ditched enclosures and the interruptions in them, interpreted as entrances). At Valencina de la Concepción in Seville, 32 complete dog skeletons were uncovered from a ditch (Figure 1: 22, Table 1: 20), (Hain 1982: 93, 140); at Marroquíes Bajos in Jaén (Figure 1: 19, Table 1: 16) a complete specimen was recovered from inside a ditch (Burgos et al. 2001b: 425); and at El Juncal in Madrid, complete dog skeletons were recovered from structures located at the ends of the ditches (Figure 1: 11, Table 1: 11), (Martínez et al. 2014: 157, Martínez et al. 2015: 248–252). Similarly, two dog skulls were found inside a ditch at Perdigões in Portugal (Figure 1: 15, Table 1: 15) (Valera 2008: 30). At Camino de las Yeseras a complete skeleton was located in a pit at the bottom of a ditched enclosure, next to the entrance. Another pit was found opposite, where another complete skeleton was found deposited together with a stone axe (Figure 1: 5, Table 1: 5), (Liesau et al. 2014b) (Figure 3).

Figure 3

Plan of the entrance of the fourth ditch at Camino de las Yeseras (Madrid) with the dog remains located at both sides. Image courtesy of Argea Consultores S.L.

Dog remains from at least seven individuals, mainly their skulls, in a large pit at Camino de las Yeseras (Madrid). Image reproduced with the permission of Argea Consultores S.L.

Methods: Traditional Osteometry vs Geometric Morphometrics

The application of traditional osteometric methodology has been in place ever since Harcourt’s (1974) publication, which revisited Koudelka’s factors (1885) to estimate the shoulder height of dogs. These estimations, along with cephalic indices, have been studied for European dog remains from the Mesolithic, and especially from the Iron Age onwards (Degerbøl 1961, Clutton-Brock 1963, Harcourt 1974, Benecke 1987, Clark 1995, De Grossi Mazzorin 2000, Sanchís & Sarrión 2004). These analyses are also useful for understanding and interpreting the dog phenomenon, as such indices have been applied to zooarchaeological measurement databases. These databases have produced results which allow characteristics of dog specimens to be derived from both long bones and cephalic indices. This has made it possible to compare osteometric data of wolves and dog breeds, and to allocate the archaeological specimens to morphotypes. Therefore, this provides useful data to the study of the dog phenomenon.

Here, traditional osteometrics have been used to compile a database. Shoulder height indices have also been used (Koudelka 1885, Harcourt 1974, Clark 1995). However, subtle changes in the shape of some bones may be difficult to detect. In order to answer some of the questions relating to the possible selection of differentiated specimens for these deposits, we used landmark-based geometric morphometrics to observe these subtle changes in the shape of the bones (Kendall 1977, 1981; Bookstein 1982, 1991; Toro-Ibacache et al. 2010).

The mandible was selected for this study as it is frequently found in the archaeological record as it is relatively robust, and because the mineralization of the teeth may favour its preservation. Also, flat bones are useful for two-dimensional (2D) geometric morphometric study. The configuration of the mandible may provide information relating to the musculature and behaviour of the animal, and even its degree of domestication (Wayne 1986, Zeder 2012). The differential development of mandibular components might reveal ontogenetic aspects related to the animal’s mechanical traction or masticatory function (Biknevicius & Leigh 1997, Segura & Flores 2009).

Eight landmarks were selected (described in Table 2, shown in Figure 5) to characterise the shape of the mandibles. Two statistical analyses were applied: Principal Component Analysis (PCA) and Canonical Variate Analysis (CVA). PCA is a variable reduction procedure, useful when data on a number of variables has been obtained (particularly where a large amount has been obtained and it is thought that there is some redundancy in those variables). In this case, redundancy means that some of the variables correlate with one another, possibly because they are measuring the same construct. It is possible to reduce the observed variables into a smaller number of principal components (artificial variables) that will account for most of the variance in the observed variables (Hatcher 1994: 2). CVA is a method to find the set of axes (or linear combination of variables) that allows for the greatest possible ability to discriminate between two or more groups. It can plot the mean of each group’s CVA axes scores on a CVA axes plot. The CVA axes, determined by a number of known groups, can assign unknown specimens to one of the known groups.

Table 2

Description of the landmarks chosen.

No. of Landmark

Description

1.

Anterior end of the symphysis between the dentary bones.

2.

Posterior edge of the canine alveolus.

3.

Posterior edge of the 2nd molar alveolus.

4.

Rearmost point of the coronoid process.

5.

Rearmost point of the angular process.

6.

Point in the mandibular ramus below posterior edge of the mandibular foramen.

7.

Point in the mandibular ramus below anterior edge of the 1st molar.

8.

Posterior end of the symphysis between the dentary bones.

Figure 5

Lateral view of the mandible of the archaeological individual from La Huelga (Palencia). Location of the 8 landmarks proposed for the mandibles is noted.

Material

For this study 53 mandibles were sampled from a range of different canid species, including archaeological individuals (n = 13), modern breeds of dogs (n = 16), wolves (n = 5) and foxes (n = 11), in addition to other canid species such as fox (Vulpes vulpes), arctic fox (Alopex lagopus), dhole (Cuon alpinus) and golden jackal (Canis aureus) (Table 3). The archaeological materials was kindly provided for this study by Corina Liesau from the Department of Prehistory and Archaeology in the Universidad Autónoma de Madrid and the directors of the archaeology companies Argea S.L. and Trébede, Patrimonio y Cultura S.L. Access to the dog and wolf comparative collection was kindly granted by Professor Arturo Morales from the Laboratorio de Arqueozoología at the Universidad Autónoma de Madrid. Modern-fox mandibles from southern Iberia were kindly loaned to the author by Dr Concepción Azorit from the Department of Animal and Plant Biology and Ecology at the Universidad de Jaén.

Table 3

Sample of mandibles used in the geometric morphometrics study. The left column shows the number used for the statistical analysis. Archaeological materials are shown in bold. All specimens with * correspond to Canis familiaris.

No.

Code

Provenance of the Material

Chronology/Breeds/Species

1.

YESEA21-001

Camino de las Yeseras – Dog in funerary context

Chalcolithic

2.

YESEA40-003

Camino de las Yeseras – Dog in a pit

Chalcolithic

3.

YESEA40-004

Camino de las Yeseras – Dog in a pit

Chalcolithic

4.

YESEA40-005

Camino de las Yeseras – Dog in a pit

Chalcolithic

5.

YESEA40-006

Camino de las Yeseras – Dog in a pit

Chalcolithic

6.

YESEA54-010

Camino de las Yeseras – Dog in a ditch

Chalcolithic

7.

YESEA134-013

Camino de las Yeseras – Dog in funerary context

Bronze Age

8.

YESEA132-017

Camino de las Yeseras – Dog in a pit

Roman Period

9.

HUELG36C-019

La Huelga – Dog in a pit

Bronze Age

10.

SCHNAU-020

LAZ-UAM Comparative collection

Schnauzer*

11.

PODORI-021

LAZ-UAM Comparative collection

Podenco orito*

12.

PODORI-022

LAZ-UAM Comparative collection

Podenco orito*

13.

GALGO-023

LAZ-UAM Comparative collection

Greyhound*

14

PAGUAS-024

LAZ-UAM Comparative collection

Perro de aguas*

15.

MASPIRI-025

LAZ-UAM Comparative collection

Mastiff*

16.

PASTAL-026

LAZ-UAM Comparative collection

German Shepherd*

17.

VIRING-028

LAZ-UAM Comparative collection

Viringo*

18.

BULLDOG-029

LAZ-UAM Comparative collection

Bulldog*

19.

HUSKY-030

LAZ-UAM Comparative collection

Husky*

20.

LABRA-031

LAZ-UAM Comparative collection

Labrador*

21.

BOXER-032

LAZ-UAM Comparative collection

Boxer*

22.

TERRANO-033

LAZ-UAM Comparative collection

Terranova*

23.

TECKEL-034

LAZ-UAM Comparative collection

Dachshund*

24.

CARLIN-035

LAZ-UAM Comparative collection

Pug*

25.

LASAPSO-036

LAZ-UAM Comparative collection

Lasha Apso*

26.

YORKTER-037

LAZ-UAM Comparative collection

Yorkshire Terrier*

27.

CHACAL-038

LAZ-UAM Comparative collection

Golden jackal (Canis aureus)

28.

CUON-039

LAZ-UAM Comparative collection

Dhole (Cuon alpinus)

29.

ZORROART-040

LAZ-UAM Comparative collection

Artic fox (Alopex lagopus)

30.

VULPES-041

LAZ-UAM Comparative collection

Fox (Vulpes vulpes)

31.

CANLUP-042

LAZ-UAM Comparative collection

Wolf (Canis lupus)

32.

CANLUP-043

LAZ-UAM Comparative collection

Wolf (Canis lupus)

33.

CANLUP-044

LAZ-UAM Comparative collection

Wolf (Canis lupus)

34.

CANLUPLJ-045

LAZ-UAM Comparative collection

Wolf (Canis lupus)

35.

CANLUPLJ-046

LAZ-UAM Comparative collection

Wolf (Canis lupus)

36.

VA10002-047

UJA Comparative collection

Fox (Vulpes vulpes)

37.

VA32203-048

UJA Comparative collection

Fox (Vulpes vulpes)

38.

UJA10C5129-049

UJA Comparative collection

Fox (Vulpes vulpes)

39.

UJA10C5129-049

UJA Comparative collection

Fox (Vulpes vulpes)

40.

VA290-051

UJA Comparative collection

Fox (Vulpes vulpes)

41.

VA32103-052

UJA Comparative collection

Fox (Vulpes vulpes)

42.

VA31-053

UJA Comparative collection

Fox (Vulpes vulpes)

43.

VA32003-054

UJA Comparative collection

Fox (Vulpes vulpes)

44.

VA7702-055

UJA Comparative collection

Fox (Vulpes vulpes)

45.

VA357/03-056

UJA Comparative collection

Fox (Vulpes vulpes)

46.

YESEA464

Camino de las Yeseras – Faunal remains

Bronze Age

47.

YESEA319

Camino de las Yeseras – Dog in a pit

Bronze Age

48.

YESEA04

Camino de las Yeseras – Faunal remains

Chalcolithic

49.

YESEA21

Camino de las Yeseras – Dogs in a pit

Chalcolithic

50.

YESEA55

Camino de las Yeseras – Faunal remains

Chalcolithic

51.

YESEA56

Camino de las Yeseras – Faunal remains

Chalcolithic

52.

YESEA61

Camino de las Yeseras – Dogs in a pit

Chalcolithic

53.

YESEA132

Camino de las Yeseras – Faunal remains

Chalcolithic

Most of the archaeological samples are from Camino de las Yeseras. These derive from both from special deposits – which follow the types of deposit explored above – and from other pits without relevant information or material. It is important to note that further research is ongoing as part of the author’s doctoral thesis, with forthcoming results exploring a number of additional specimens.

Results

Traditional indices for shoulder height suggest a mean measurement of 44–47 cm, and a 7–9 range mean for the stoutness of our specimens (Appendix 1).

The PCA analyses did not reveal groups or striking differences between these archaeological specimens (Figure 6), whereas the application of CVA did show a different spread to that obtained through PCA (Figure 7).

Figure 6

Analysis of the Principal Components (PC1 and PC2). The mean is represented by a large symbol for each group. While foxes or brachycephalic dogs from the modern dogs collection are clearly separated, most of the other modern breeds and archaeological specimens are largely mixed. See Table 3 for the identifying number for each individual.

Figure 7

Canonical variate analysis (CV1 and CV2). The foxes group is, as expected, clearly separated from the rest. Although close together, two groups are defined: the wolves and archaeological individuals group, and the modern breeds group, mixed with some archaeological individuals. The identifying number for each individual is in Table 3.

The archaeological mandibles appear less similar than initially interpreted. Figure 7 shows that although the archaeological mandibles all fall within a similar range on the y-axis, a division can be observed within the results. This suggests the presence of two distinct groups within the archaeological samples. The first group in the CVA appears close to that of modern dog breeds. These specimens were recovered from special deposits at Camino de las Yeseras. Point number 1 is one of two dogs associated with the Bell-Beaker tomb which had evidence of sacrifice. Point number 7 represents a dog from a Bronze Age child burial. Finally, point number 6 represents a dog found on one of the sides of a ditch (Figure 3, Table 1).

The variability put forward by CVA analyses allow to consider differences among dog mandibles in the archaeological record studied.

Discussion and Conclusions

The important social role of dogs can be inferred by the typical presence of numerous complete skeletons late prehistoric sites in the Iberian Peninsula. As previously mentioned, dog remains have been recovered from a range of different contexts, including burials, pits, and outstanding locations. The different contexts which dog remains have been recovered from may suggest that dogs were used for numerous different purposes in the Iberian Peninsula during Late Prehistory (Figure 1, Table 1). Additionally, this may also reflect the manner in which dogs were perceived by human societies. It may be that this varied across sites, or that dogs encompassed an important role in ideology and symbolism within Late Prehistoric Iberia. The repeated placement of dog remains in particular as special deposits (Grant 1984, Hamerow 2006: 1–2) is something I consider to be sufficiently noteworthy to be considered a dog phenomenon.

The preparation of a catalogue of deposited dog remains allows for a series of commonalities to be observed amongst registered dog osteological remains. Differences are also noted, which leads us to propose ordering these deposits in different typologies. This research has demonstrated both the location and quantity of dog remains deposits from the Iberian Peninsula and also the different contexts in which they are placed. Important contrasts have been found which, I argue, refer to different reasons for placement. Further research will consider the importance of the archaeological data alongside bone assemblages and also investigate possible ethnographic parallels.

Traditional osteometry is useful for the development of specimen databases, but in our study did not prove sufficiently valuable when trying to identify subtle morphological differences. The limited number of results obtained when applying indices to the (often badly preserved) archaeological material, made this a difficult task to undertake. These applications show apparent homogeneity between individuals. Geometric Morphometrics could provide important information in this regard.

Geometric Morphometrics have been used to determine issues relating to the origins of domestication, providing important results in addition to the development of new lines of multi-disciplinary combined research (Larson et al. 2014, Drake et al. 2015). Here the study focuses on domestic species. Studies from later periods have allowed assignment of archaeological dog remains to different morphotypes of dogs based on differing osteometry and statistics (Morales et al. 2015). In our sample of dog remains from Iberian Late Prehistory, we have to deal with very subtle osteological/morphological differences between individuals, and, often the remains are in a poor state of preservation. Overall the application of Geometric Morphometrics seems to have a great potential that should be further developed and investigated.

Our preliminary results from the 2D geometric morphometric study have provided interesting preliminary results regarding the selected archaeozoological material. Using the same skeletal element for different individuals, it was possible to detect slight differences in the osteological remains. Considering bone preservation, the number of mandibles present per site and the fact that mandibles usually exhibit zones useful to osteometric and morphological study, these preliminary results proved useful in guiding the author’s future research.

The CVA analysis appears to show that there is a specific configuration of the mandible in some dog specimens from the archaeological sample. Most morphological features are subtle and relative to changes in shape, so that statistically significant differences could only be detected and discussed using the results from the geometric morphometrics analysis. This technique seems to reveal that archaeological dogs might present a morphotype variability that went undetected by the standard osteometry indices. We have begun assigning some dogs to the closest morphological group represented by modern specimens.

Following these preliminary results, further research will allow additional interpretations to be made. This aims to explore whether these dogs were intentionally selected for placement in particular deposits because of their morphological characteristics. In such cases, this could represent a different symbolic connotation.

Ongoing PhD research by the author is extending the preliminary research presented in this paper, expanding both the sample size and the geometric morphometrics-based approach. Further results are to be subjected to rigorous statistical analysis as part of the doctoral thesis, and to consider whether the separate groupings form a distinct pattern. From this it will be possible provide a comprehensive overview of deposited dog remains in the Later Prehistory of the Iberian Peninsula.

Additional File

Results of shoulder height and bone stoutness for specimens found in Iberian Late Prehistoric Sites througt the application of indexes from some authors (Harcourt 1885, Koudelka 1974, Clark 1975) to measumerements. Individual measurements with * from Sanchís and Sarrión (2004). Individual measurements with ** from Liesau, Esparza and Sánchez (2014). DOI: https://doi.org/10.5334/pia-487.s1

Acknowledgements

In studying the material presented here I have benefitted greatly from the help of numerous people. I am most grateful to Corina Liesau (Department of Prehistory and Archaeology, UAM), Arturo Morales (Department of Biology, UAM and Laboratorio de Arqueozoología LAZ-UAM) and Concepción Azorit (Department of Animal and Plant Biology and Ecology, UJA) for sharing knowledge and materials with me. Laura Llorente (University of York and LAZ-UAM) and Carlos Arteaga (Department of Geography, UAM) kindly read and commented on an earlier version of this paper. I also wish to thank Patricia Ríos (Department of Prehistory and Archaeology, UAM) for her help with the geographical information, and for her and Laura Llorente’s comments on the final version of this manuscript. I am also grateful to Argea Consultores S.L. and Trébede, Patrimonio y Cultura S.L. for the archaeological materials. Finally, I would like to extend my sincerest thanks to Markus Bastir (National Museum of Natural Sciences, MNCN and Superior Council of Scientific Research, CSIC), Daniel García (MNCN-CSIC) and Soledad de Esteban-Trivingo (Miquel Crusafont Catalan Institute of Paleontology, ICP and Transmitting Science) for advice on future analysis.

Competing Interests

This research was performed as part of the project “Las sociedades calcolíticas y su marco temporal en la región de Madrid. Una revisión a la luz de nuevos datos (HAR 2011 28731)” (PI: Corina Liesau), funded by the Ministry of Economy and Competitiveness of the Government of Spain. A. Daza Perea’s work was funded by the Spanish Ministry of Economy and Competitiveness through a FPI PhD grant (grant code BES-2012-056461).

Author Information

Financial support was provided by Project HAR 2011 28731 “Las sociedades calcolíticas y su marco temporal en la región de Madrid. Una revisión a la luz de nuevos datos” and a PhD grant BES-2012-056461 from the Ministry of Economy and Competitiveness of the Government of Spain.

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